My supercharger has been making diesel sounds (at idle) for some time (despite my SLK having only 40,000mi since brand new), and I am finally wanting to pull it and inspect it.

I have been assured (we'll see) that it's most likely the coupling disk, and have one ready to install.

My question is on removal.

Is it easily removed with the car on a flat surface, or is there any need to have it on a lift?

I have a shop w/ a 2-Post lift, but it's always tied up with friends' cars, so if I could just do it in the bay next to my lift bay (and not tying up the lift while my SLK is apart) it would be preferable.

After removal, I've been told that if I mount it vertically in a vise, I can remove the nose for disk replacement without draining the oil inside (which everyone has told me should be OK at 40k miles). Beside replacing the disk, what inspections or tests should I do, or replacement undertake while the S/C is off the car? How much supercharger oil (GM S/C is what I've been told to use) should I get in preparation should I drain/refill my unit while out of the vehicle?

I also want to change the hydraulic chain tensioner as the first few seconds after start after the car has been sitting a long (it often sits for weeks between uses) time always start quiet for a couple of seconds until the tensioner piston is pushed back, then I hear chain rattle for a second or seconds and a half, then it is utterly silent from then on. Hot starts, or starts if the car has only sat a day or two are quiet.

I've been told that the tensioner is supposed to have a one-way ratcheting function specifically so once extended, it will not retract and be noisy while awaiting oil pressure. I purchased a new tensioner, and plan to install it when the supercharger is removed for inspection and whatever else it needs.

Any comments on ANYTHING I've said or proposed would be most welcome!

Bob

 

I have the rattle on start-up after 3 or more days standing. Not long after a major service, I had this loud rattling on start-up, after standing for 3 or more days - it begins immediately on turning the key and only lasts for a second then goes quiet. Sounds like it could be the timing chain tensioner has failed but I have been doing some research and it may not be that?

The problem appears to be that the oil drains out of the chain tensioner so it has to wait for pressure to build up to push it back onto the chain. This suggests that the tensioner may be OK and the problem is the failure of one of the two oil relief valves that stop oil draining back into the sump when the engine is not running. There is one behind the pulley housing that is the most likely culprit and worth changing as a matter of course while repairing your supercharger. There is another valve in the oil filter.

I also noticed that there appears to be two types of chain tensioner. One has a ratchet in it and the other relies entirely on oil pressure. I have watched youtube videos on both types that show how to "repair" them. I doubt they wear out (opinion) and might only need cleaning if there is a blocked oil way?

I hope this helps and please let me know if you can take this any further.

Roger and out

 

I didn't know there was one behind the pulley housing. Is it ONLY accessible w/ the SC removed? I just R+R's the SC and though it's not an awful job, I am not eager to do it again.

Not sure how to access the one in the oil filter canister, either.

My installed tensioner was the ratchet type, and appeared Ok when I removed it, but replaced it with a new one anyway, also the ratchet type, and my start-up noise remained the same so I suspect the tensioner is not getting especially loose, and may not have been the source of the noise, especially given my engine has only 44k miles on it. The ratchet even w/o oil pressure should maintain enough tension to prevent noise with a good chain I would think, though the same 3 days allows the noise as does yours.